Question

我一直在关注这些教程，我正处于创建ArrayAdapter的阶段，并使用布局名称和ID定义我想要显示的内容。 e.g。

整个JAVA代码：

public class MainActivity extends ActionBarActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    if (savedInstanceState == null) {
        getSupportFragmentManager().beginTransaction()
                .add(R.id.container, new PlaceholderFragment())
                .commit();
    }
}


@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();
    if (id == R.id.action_settings) {
        return true;
    }
    return super.onOptionsItemSelected(item);
}

/**
 * A placeholder fragment containing a simple view.
 */
public static class PlaceholderFragment extends Fragment {

    public PlaceholderFragment() {
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.fragment_main, container, false);

        //Creating some dummy data to be added on the screen
        String[] forecastArray = {
                "Today - Sunny - 88/63",
                "Tomorrow - Foggy - 70/40",
                "Weds - Cloudy - 72/63",
                "Thurs - Asteroids - 75/65",
                "Friday - Heavy rains - 65/56",
                "Sat - Stormy - 60/51",
                "Sun - Sunny - 80/68"
        };

        // Puts the dummy data into a ArrayList.
        List<String> weekForecast = new ArrayList<String>(
                Arrays.asList(forecastArray));

        // Now create the ArrayAdapter which will take data from a source (like the dummy forecast data I created).
        // ArrayAdapter will use the dummy data and populate the ListView it's attached to.
        mForecatAdapter = new ArrayAdapter<String>(
                getActivity(),
                R.layout.list_item_forecast,
                R.id.list_item_forecast_textView,
                weekForecast);

        return rootView;
    }
}

}

ListView的XML代码：

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin"
tools:context=".MainActivity$PlaceholderFragment">

<ListView
    android:id="@+id/listview_forecast"
    android:layout_width="match_parent"
    android:layout_height="match_parent "/>

为什么运行应用程序时不会显示存储在ArrayList中的数据？

我正在使用ListView来查看我的数据。

请帮助第一天做android开发!!

屏幕上不会显示任何内容

0 个答案: